27. In Fig. 105, if AOB and COD are straight lines. Then, x + y =
(a) 120
(b) 140
(c) 100
(d) 160
A
4
(7x-20)
o
S
с
3x
y
D
B.
Fig. 105
-can someone pls tell me how to paste diagram
Answers
Answered by
1
Answer:
Correct option is
B
140
In figure, ∠AOC=∠BOD (VOA)
∠AOC=3x
o
∠AOD=y
o
(VOA)
y
o
=(7x−20)
o
∠AOC+∠COB+∠BOD+∠AOD=360
o
3x+(7x−20)+3x+(7x−20)=360
o
3x+7x−20+3x+7x−20=360
o
20x−40=360
o
20x=360
o
+40
20x=400
o
x=20
o
So, ∠BOD=3x
o
=3×20
o
=60
o
∠BOC=y
o
=7x−30=7×20
o
−20=120
o
x+y=20+120=140
o
Similar questions